pwd -LP

pwd.c

@@ -1,11 +1,44 @@
 /* See LICENSE file for copyright and license details. */
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
+#include <sys/stat.h>
 #include "util.h"
 
+static const char *getpwd(const char *cwd);
+
 int
-main(void)
+main(int argc, char *argv[])
 {
-	puts(agetcwd());
+	char *cwd, c;
+	char mode = 'L';
+
+	while((c = getopt(argc, argv, "LP")) != -1)
+		switch(c) {
+		case 'L':
+		case 'P':
+			mode = c;
+			break;
+		default:
+			exit(EXIT_FAILURE);
+		}
+	cwd = agetcwd();
+	puts((mode == 'L') ? getpwd(cwd) : cwd);
 	return EXIT_SUCCESS;
 }
+
+const char *
+getpwd(const char *cwd)
+{
+	const char *pwd;
+	struct stat cst, pst;
+
+	if(!(pwd = getenv("PWD")) || pwd[0] != '/' || stat(pwd, &pst) != 0)
+		return cwd;
+	if(stat(cwd, &cst) != 0)
+		eprintf("stat %s:", cwd);
+	if(pst.st_dev == cst.st_dev && pst.st_ino == cst.st_ino)
+		return pwd;
+	else
+		return cwd;
+}